JP7418949B2 - Display device, imaging device - Google Patents

Description

The present invention relates to a display device having a plurality of EL elements and an imaging device having the same.

An organic EL element is a light emitting element that has a pair of electrodes and an organic compound layer disposed between them. Organic EL elements are being put to practical use as light-emitting devices such as thin displays, lighting equipment, head-mounted displays, and light sources for print heads of electrophotographic printers, taking advantage of their superior features such as surface-emitting properties, light weight, and visibility.

In particular, the demand for higher definition of organic EL display devices is increasing, and a system using a white organic EL element and a color filter (hereinafter referred to as a white+CF system) is known. The white + CF method is a method in which a plurality of color filters having different wavelength dispersions of absorbed light are installed in the emission direction of white light emitted by an organic EL element. For example, by forming color filters for each color so that the colors of light emitted after passing through the color filters are red, green, and blue, full-color display by additive color mixture becomes possible. Further, since the white+CF method does not require forming an organic compound layer for each light-emitting pixel, it is easy to increase the definition of the light-emitting pixels.

By the way, in white+CF type organic EL display devices, a reduction in color purity of emitted light color has become a problem. It is known that one of the causes of this problem is that when a pixel of a certain color is emitted, stray light is emitted from the color filter of the adjacent pixel.

FIG. 7 shows a conventional organic EL display device. The organic EL display device has a first organic EL element and a second organic EL element. It is known that in general, about 80% of the light emitted by an organic EL element becomes guided light that is guided through an organic compound layer or a sealing layer. The guided light is guided in the horizontal direction within the organic EL display device by reflection of the light from the surfaces of the lower electrode, the substrate, the insulating layer, etc., and the light output side surface of the upper electrode and the sealing film.

When the surfaces of the lower electrode and the upper electrode are parallel to the substrate, guided light tends to be guided in the horizontal direction. If there is a structure that is not parallel to the substrate, the guided light will be reflected, refracted, or scattered, resulting in stray light, and some of the stray light will be directed from the position of the structure in a direction perpendicular to the substrate, that is, in the light output direction. proceed. As shown in FIG. 7, for example, a part of the light emitted by the second organic EL element becomes stray light at the inclined portion of the first organic EL element, and is transmitted through the first color filter. In such a case, the color purity of the second organic EL element decreases because the emitted light includes the light transmitted through the first color filter in addition to the light transmitted through the second color filter.

Patent Document 1 discloses an organic EL display device in which a metal light-shielding layer is provided on a color filter, and further, an end of a color filter and an end of an adjacent color filter are overlapped to suppress color mixture.

Japanese Patent Application Publication No. 2013-20744

The organic EL display device described in Patent Document 1 suppresses color mixture by providing a metal light shielding layer in a portion where two types of color filters overlap.

However, it is necessary to provide a metal light-shielding layer, and depending on the structure of the display device, it is necessary to consider the reflection of the metal light-shielding layer and the influence on the protective layer, so there is room for improvement.

On the other hand, by increasing the area where color filters overlap, it is possible to improve the color purity of the emitted color, but if the area where all color filters overlap is increased, the aperture ratio becomes smaller and the brightness decreases. Since this decreases, improvement has been desired.

An object of the present invention is to provide an organic EL display device that suppresses reduction in aperture ratio and has a high color gamut.

The present invention has a first EL element and a second EL element on a substrate, and the first EL element includes a lower electrode, a light emitting layer, an upper electrode, a second EL element, and a lower electrode, a light emitting layer, an upper electrode, and a second EL element on the substrate. The second EL element has a lower electrode, a light emitting layer, an upper electrode, and a second color filter in this order from the substrate side. an overlapping region including an insulating layer covering the lower electrode of the EL element and the lower electrode of the second EL element, where the first color filter and the second color filter overlap in plan view; The visibility of the light passing through the first color filter is greater than the visibility of light passing through the second color filter, and the visibility of the light passing through the first color filter is greater than the visibility of light passing through the second color filter. The distance L2 between the end on the color filter side and the end on the first EL element side of the second color filter is the same as that of the second color filter in the light emitting region of the first EL element. A display device that is larger than a distance L1 between a side end of the first color filter and an end of the first color filter on the second EL element side,
The insulating layer has a recess between the first EL element and the second EL element, the recess having an inclined part on the first EL element side and an inclined part on the second EL element side. In a plan view, the inclined portion on the first EL element side and the overlapping region overlap, and the inclined portion on the second EL element side and the overlapping region overlap. To provide a display device characterized in that at least a portion of the display device does not overlap .

According to the present invention, it is possible to provide an organic EL display device that suppresses reduction in aperture ratio and has high color reproducibility.

1 is a schematic cross-sectional view showing an example of an organic EL display device according to the present invention. FIG. 2 is a schematic cross-sectional view showing a transmission region of a color filter of an organic EL display device according to the present invention. (a) It is a graph showing an emission spectrum and a visibility curve. (b) It is an enlarged view of the low intensity spectrum part in (a). It is a figure explaining visibility using a standard ratio luminosity curve. FIG. 2 is a schematic cross-sectional view showing an example of an inclined portion of an organic EL display device according to the present invention. FIG. 3 is a diagram showing the relationship between an example of an organic EL display device and a slope portion according to the present invention. FIG. 1 is a cross-sectional view showing an example of a conventional display device. FIG. 1 is a cross-sectional view showing an example of a conventional display device. FIG. 1 is a schematic diagram showing an example of a display device according to the present embodiment. FIG. 1 is a schematic diagram showing an example of an imaging device according to the present embodiment. FIG. 1 is a schematic diagram showing an example of a mobile device according to the present embodiment. (a) It is a schematic diagram showing an example of the display device concerning this embodiment. (b) It is a schematic diagram showing an example of a foldable display device.

The present invention is a display device that includes a light-emitting layer that emits white light, and suppresses white light from becoming guided light and being emitted from adjacent pixels and deteriorating color reproducibility. A color filter that transmits light with low visibility is arranged closer to the light emitting area of an adjacent pixel. It can also be said that the width of the color filter that transmits light with low visibility is larger than that of other color filters.

The display device according to the present embodiment includes, on a substrate, a first EL element having a first color filter and a second EL element having a second color filter; The display device has an overlapping region where a color filter and the second color filter overlap in plan view.

The visibility of light passing through the first color filter may be greater than the visibility of light passing through the second color filter.

The distance L2 between the end of the light emitting region of the second EL element on the first color filter side and the end of the second color filter on the first EL element side is equal to It is larger than the distance L1 between the end of the light emitting region of one EL element on the second color filter side and the end of the first color filter on the second EL element side.

Note that in this specification, a plan view refers to a view from a direction perpendicular to the main surface of the substrate.

Since the color filter that transmits light with low visibility has a large area, the area where only the color filter that transmits light with high visibility is transmitted and emitted is narrowed. As a result, stray light within the display device becomes light with high visibility and is not emitted, resulting in a display device with excellent color reproducibility.

In the display device according to this embodiment, L2 may be 25% or more larger than L1. The ratio is calculated as (L2-L1)/L1. More preferably, it is 75% or more larger.

Further, L2 may be larger than L1 by 0.2 μm or more. More preferably, it is larger than 0.6 μm.

(Organic EL display device according to this embodiment)
Hereinafter, preferred embodiments of the organic EL display device of the present invention will be described with reference to the drawings. Note that for parts not particularly shown or described in this specification, well-known or well-known techniques in the relevant technical field are applied. Furthermore, the present invention is not limited to the embodiments described below.

FIG. 1 is a schematic cross-sectional view showing an example of an organic EL display device according to this embodiment. Although the EL element is described as an organic EL element, it is not limited thereto. In the display device of FIG. 1, a first organic EL element 100 and a second organic EL element 200 are formed on a substrate 1. The first organic EL element 100 and the second organic EL element 200 each include a lower electrode 2, an organic compound layer 3 including a light emitting layer, an upper electrode 4, and a color filter.

A first color filter 101 is arranged on the light output side of the upper electrode of the first organic EL element 100, and a second color filter 201 is arranged on the light output side of the upper electrode of the second organic EL element. It's okay to be. It may be arranged so as to overlap with the first light emitting region 102 in plan view. It may be arranged so as to overlap with the second light emitting region 202 in plan view.

In Figure 1, the first color filter overlaps so that it is closer to the substrate than the second color filter, but even if the second color filter overlaps so that it is closer to the substrate than the first color filter, good.

Further, the first color filter and the second color filter only need to overlap in plan view, and do not need to be in contact with each other, but it is preferable that they are in contact with each other because it is easier to suppress color mixture.

The effect of the first color filter 101 and the second color filter 201 overlapping in plan view will be explained.

A portion of the light emitted from the second light emitting region passes through the second color filter and is emitted to the outside of the organic EL display device. On the other hand, a part of the light emitted from the second light emitting region becomes stray light due to reflection, refraction, and scattering at the inclined portion within the organic EL display device.

Specifically, the sloped portion includes the edge of the lower electrode, the opening of the insulating layer, the organic compound layer, the upper electrode, the sealing film, etc. along the slope of the edge of the lower electrode and the opening of the insulating layer, etc. This is the part that is not parallel to the substrate.

Of the stray light, the light that travels in the direction perpendicular to the substrate passes through the first color filter and then goes to the second color filter, but the first color filter and the second color filter absorb the light. Since the wavelength dispersion is different, the stray light is absorbed by the second color filter. Since stray light is not emitted from the first color filter, the color purity of the second organic EL element can be improved.

On the other hand, if the amount of overlapping of the color filters of all organic EL elements is increased, the area through which the emitted light passes through the color filters decreases, which tends to reduce the brightness of the organic EL display device. It is preferable to increase the overlap area between the two.

FIG. 8 is a schematic cross-sectional view showing a display device of a reference example. A conceptual diagram of a cross section when the amount of overlapping of color filters of all EL elements is increased is shown. The overlapping region 21 where color filters with different wavelength dispersions of absorbed light overlap becomes a light-blocking region. Therefore, if the amount of overlapping of the color filters of all organic EL elements is increased, the overlapping region 21 will be large and the transmitting region 20 will be small. Become.

In such a case, the brightness decreases significantly when viewed from the front or diagonally. On the other hand, when the overlapping amount of some of the color filters is increased as shown in FIG. 2, the transmission area is large, so that reduction in brightness of the display device can be reduced.

Next, the effects of emitted light color and color mixture on the emitted light color and chromaticity change will be explained.

FIG. 3 shows an emission spectrum when 3% of green emission is mixed with red emission. 3% represents the intensity ratio. In FIG. 3(a), the emission peak of Red is seen around 610 nm. FIG. 3(b) is an enlarged graph of the low-intensity portion of FIG. 3(a). A green peak is seen at around 525 nm with an intensity of 3% of the red peak. Such color mixture causes a decrease in the color purity of the emitted color.

Table 1 shows the amount of change Δu'v' in chromaticity u'v' when 3% of other colors are mixed for each emitted color. When Red is mixed with Green, when Blue is mixed with Green, and when Blue is mixed with Red, the amount of chromaticity change Δu'v' is large. That is, when light having higher visibility than the emitted color is mixed, the amount of chromaticity change is large. On the other hand, when light with lower visibility than the emitted color is mixed, the amount of chromaticity change is less than half of that when light with higher visibility is mixed.

In this way, it can be seen that the degree of influence on chromaticity differs depending on the combination of the emitted light color and the mixed color.

The reason why the degree of influence on chromaticity differs depending on the combination of emitted color and mixed color is that when the visibility of mixed color light is higher than the visibility of light of emitted color, the effect on chromaticity change is greater. It's for a reason.

Visibility, also called spectral luminous efficacy, expresses the degree to which the human eye perceives the brightness of other wavelengths, with light at a wavelength of approximately 555 nm being perceived most strongly in a vacuum as 1. Furthermore, the average luminous efficiency of a large number of people, agreed upon by the Commission Internationale de l'Eclairage (CIE), is called standard relative luminous efficiency (comparative luminous efficiency).

In this specification, the luminous efficiency can be estimated from the maximum peak wavelength of the emission spectrum and the standard relative luminous efficiency. Visibility is green>red>blue.

Here, the definition of visibility of the emission spectrum will be explained. FIG. 4 shows the emission spectrum of light passing through the color filter. As an example, an emission spectrum of red, green, and blue emission colors after transmission was shown. The emission spectrum is normalized so that the peak intensity is 1. The luminous efficiency Y of the luminescent spectrum is the value obtained by multiplying this luminous spectrum EL (λ) by the standard luminous efficiency curve y (λ) for each wavelength and integrating the result. The calculation formula is shown in equation (1).

For example, the visibility of each of the Red, Green, and Blue emission spectra in FIG. 4 is 17 for Red, 31 for Green, and 4 for Blue from equation (1).

In Table 1, a combination with a large amount of chromaticity change is a case where a luminescent color with low visibility is mixed with a luminescent color with high visibility.

Therefore, in order to increase the chromaticity improvement effect without enlarging the overlapping areas of all the color filters, it is preferable to suppress color mixture in combinations of mixed colors that have a large amount of chromaticity change. That is, it is preferable to increase the overlapping amount of color filters of luminescent colors with low visibility, and to suppress color mixing of luminescent colors with high visibility.

Regarding the relationship between the luminescent colors of the first organic EL element and the second organic EL element, the combinations shown in Table 2 are preferable from the relationship of the visibility values.

Moreover, it is preferable that the second color filter overlaps the step portion of the first organic EL element on the second organic EL element side in plan view. As described above, since the guided light becomes stray light at a location where there is a stepped portion, it is preferable that the second color filter overlaps the location where stray light occurs in plan view.

Examples of the stepped portion of the EL element include an insulating layer that covers the end of the lower electrode. As a result of the insulating layer creating a step, components above the lower electrode may be affected by the step.

FIG. 5 is a schematic cross-sectional view of an example of an organic EL display device according to this embodiment. The second color filter includes a step 110 at the end of the lower electrode 2 of the first organic EL element on the second organic EL element side, a step 111 of the insulating layer 5 above the step 110, and an organic compound on the step 111. It is preferable that the step 112 of the layer or the upper electrode and the step 113 of the protective layer 6 above the step 112 overlap in plan view.

The second color filter also includes a step 121 of the opening of the insulating layer 5 in the first organic EL element on the second organic EL element side, a step 122 of the organic compound layer or upper electrode on the step 121, and a step 122 of the organic compound layer or upper electrode on the step 121. It is preferable that the step portion 123 of the protective layer 6 on the portion 122 overlaps with the stepped portion 123 in a plan view.

(Other embodiments)
The display device according to this embodiment may include the third organic EL element 300 adjacent to the second organic EL element 200. The third organic EL element 300 in FIG. 1 has a third color filter 302. The third color filter transmits light of a different wavelength from both the first color filter and the second color filter. That is, the third color filter has wavelength dispersion that is different from both the first color filter and the second color filter.

Furthermore, the same relationship as that between the first color filter 302 and the second color filter 202 can be applied to the relationship between the third color filter 302 and the second color filter 202.

That is, the third color filter 301 and the second color filter 201 are arranged so as to overlap in plan view. The distance L4 between the end of the second light emitting region on the third light emitting region side and the end of the second color filter on the third light emitting region side is the distance L4 between the end of the second light emitting region 302 on the second light emitting region side. is larger than the distance L3 in plan view between the end of the third color filter and the end of the third color filter on the second light emitting region side.

In addition, the visibility of the emission spectrum of the third organic EL element may be greater than the visibility of the emission spectrum of the second organic EL element. The combination of the emission colors of the first organic EL element, the second organic EL element, and the third organic EL element is, for example, the emission color of the first organic EL element is Green, and the emission color of the second organic EL element is Green. It is possible to set the color of the third organic EL element to be Blue and the color of light emitted from the third organic EL element to be Red.

It is possible to consider each of the first organic EL element 100, the second organic EL element 200, and the third organic EL element 300 as a subpixel, and the three subpixels as one main pixel. Full-color display is possible through additive color mixing of these subpixels.

The planar arrangement of the first organic EL element 100, the second organic EL element 200, and the third organic EL element 300 may be any of a stripe arrangement, a square arrangement, a delta arrangement, and a Bayer arrangement. Furthermore, by arranging the main pixels in a matrix, an organic EL display device with a large number of pixels becomes possible.

(Configuration of organic EL element according to this embodiment)
The substrate 1 is not limited as long as it can support the lower electrode 2, organic compound layer 3, and upper electrode 4. For example, glass, plastic, silicon, etc. are suitable. A switching element such as a transistor, wiring, an interlayer insulating film (not shown), etc. may be formed on the substrate 1.

The lower electrodes 2 of the first organic EL element 100 and the second organic EL element 200 are electrically separated. From the viewpoint of luminous efficiency, the lower electrode 2 is preferably made of a metal material with a visible light reflectance of 50% or more. Specifically, metals such as Al and Ag, and alloys in which Si, Cu, Ni, Nd, Ti, etc. are added to these metals can be used. Further, the reflective electrode may have a barrier layer on the surface on the light emission side. As the material for the barrier layer, metals such as Ti, W, Mo, and Au or alloys thereof, or transparent conductive oxides such as ITO and IZO are preferable. In order to optimize optical interference, the film thickness of the transparent conductive oxide may be different between the first organic EL element 100 and the second organic EL element 200.

The organic compound layer 3 is disposed across the lower electrode of the first organic EL element and the lower electrode of the second organic EL element, and can be formed by a known technique such as vapor deposition or spin coating. When the organic compound layer is formed across a plurality of lower electrodes, it can be said that it is a common layer on a plurality of lower electrodes. It can also be said that they are formed continuously. Formed continuously means that the organic compound layer is formed substantially without interruption, and does not necessarily have to be formed in a continuous process.

The organic compound layer 3 is a layer that includes at least a light emitting layer, and may be composed of a plurality of layers. Examples of the plurality of layers include a hole injection layer, a hole transport layer, an electron block layer, a light emitting layer, a hole block layer, an electron transport layer, and an electron injection layer. These layers are not limited to those made only of organic compounds, but may also contain inorganic compounds. Since the main light emission is emitted from an organic compound, it can be called an organic EL element.

In the organic compound layer, holes injected from the anode and electrons injected from the cathode recombine in the light emitting layer, thereby emitting white light from the light emitting layer. The light-emitting layer may be composed of a plurality of layers, and each light-emitting layer can have a red light-emitting material, a green light-emitting material, or a red light-emitting material, and white light can be obtained by mixing each light-emitting color. Furthermore, each of the light-emitting layers may include a light-emitting material having a complementary color relationship, such as a blue light-emitting material and a yellow light-emitting material.

An electron injection layer (not shown) may be disposed between the organic compound layer 3 and the upper electrode 4. It is preferable to use a compound with high electron donating properties for the electron injection layer. The compound with high electron donating property preferably includes metals with high electron donating property such as alkali metals such as lithium and cesium, alkaline earth metals such as calcium and barium, and compounds thereof. It may also be an organometallic complex in which these metals and organic compounds are combined. These materials may be a single layer or may be a mixed layer with the organic compound of the electron transport layer.

The upper electrode 4 is disposed across the organic compound layer 3 of the first organic EL element and the organic compound layer 3 of the second organic EL element, and has translucency. The upper electrode 4 may be a semi-transparent material having a property of transmitting part of the light that reaches its surface and reflecting the other part (ie, semi-transparent reflective property). The material constituting the upper electrode 4 is, for example, a transparent material such as a transparent conductive oxide, a simple metal such as aluminum, silver, or gold, an alkali metal such as lithium or cesium, or an alkaline earth metal such as magnesium, calcium, or barium. It is composed of a semi-transparent material made of metal or an alloy material containing these metal materials. The semi-transparent material is particularly preferably an alloy containing magnesium or silver as a main component. Further, the upper electrode 4 may have a laminated structure of the above materials as long as it has a preferable transmittance.

In this embodiment, the lower electrode 2 is an anode and the upper electrode 4 is a cathode, but the lower electrode 2 may be a cathode and the upper electrode 4 may be an anode.

The organic EL display device according to the present embodiment may have an insulating layer 5 between the adjacent first organic EL element 100 and second organic EL element 200. The insulating layer 5 is provided so as to cover the ends of the lower electrodes 2 of each of the first organic EL element 100 and the second organic EL element 200, and has an opening so that a part of the lower electrode is exposed.

The insulating layer 5 may be formed to give the first light emitting region 102 and the second light emitting region 202 exactly the desired shape. When the insulating layer 5 is not provided, the first light emitting region 102 and the second light emitting region 202 are defined by the lower electrode 2.

The insulating layer 5 may be made of an inorganic material such as silicon nitride (SiN), silicon oxynitride (SiON), or silicon oxide (SiO). The insulating layer can be formed using known techniques such as sputtering and chemical vapor deposition (CVD). Further, the insulating layer 5 may be made of an organic material such as acrylic resin or polyimide resin.

The organic EL display device according to this embodiment may include a protective layer 6. The protective layer may be disposed to cover the first organic EL element 100 and the second organic EL element 200. The protective layer 6 preferably contains an inorganic material that is transparent and has extremely low permeability to oxygen and moisture from the outside, particularly silicon nitride (SiN), silicon oxynitride (SiON), and silicon oxide. (SiOx), aluminum oxide (Al2O3), titanium oxide (TiO2), etc. are preferable.

The protective layer 6 can be formed by sputtering, chemical vapor deposition (CVD), or atomic layer deposition (ALD). The protective layer 6 may take the form of either a single layer or a laminate of the above-mentioned materials, as long as it has sufficient moisture-blocking performance, and may also have a laminate structure of the above-mentioned inorganic and organic materials. As the organic material, a known organic compound (resin/polymer compound) can be used. Further, the protective layer 6 may have irregularities that follow the shape of the structure formed before the protective layer 6. The protective layer can also be called a sealing layer. Even if it is called a sealing layer, its ability to seal the display device does not have to be perfect.

In the organic EL display device according to this embodiment, the planarization layer 7 may be formed between the protective layer 6 and the color filter. The planarization layer 7 is formed of a material having translucency, and may be either an inorganic material or an organic material. When the flattening layer 7 is formed of a resin material, the unevenness on the light exit side of the flattening layer 7 is smaller than that of the protective layer, so it is possible to reduce scattered light due to the unevenness of the protective layer 6. The planarization layer can also be called a coat layer.

The planarization layer may be made of an organic material such as acrylic resin, epoxy resin, silicone resin, etc., for example. The planarizing layer can be formed by a known method such as a coating method or a polymerization vapor deposition method.

In the organic EL display device according to this embodiment, the filling layer 8 may be arranged on the light output side of the color filter. The filling layer 8 has a light-transmitting property, is made of an organic material such as an acrylic resin, an epoxy resin, or a silicone resin, and is preferably flat on the light exit side. Particularly when a counter substrate, which will be described later, is not provided, it is preferable that the light exit side of the filling layer 8 is flat. Further, a flattening layer may be formed between the color filter and the filling layer.

The filling layer and the flattening layer disposed between the color filter and the protective layer may be made of the same material. The filling layer and the planarization layer may meet outside the display area, ie at the edge of the display device. It is preferable that they are made of the same material because of their high adhesion.

In the organic EL display device according to this embodiment, the counter substrate 9 may be arranged on the light output side of the filling layer 8. The counter substrate 9 is made of a transparent material. The counter substrate 9 is made of, for example, a glass substrate, a plastic substrate, or the like, and preferably has a flat light-emitting side.

The color filter according to this embodiment may be formed directly on the protective layer or the planarization layer, or a counter substrate on which the color filter has been formed in advance may be placed opposite the first organic EL element and the second organic EL element. May be combined with When combined with a transparent substrate on which a color filter is formed, it is more preferable that there is no gap between the first organic EL element and the second organic EL element and the color filter. The void can be filled with a known resin or the like.

Color filters are coated with a color resist and patterned using lithography. The color resist is made of, for example, a photocurable resin, and forms a pattern by curing the portions irradiated with ultraviolet rays or the like.

FIG. 9 is a schematic diagram showing an example of a display device according to this embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. Flexible printed circuits FPCs 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. A transistor is printed on the printed circuit board 1007. The battery 1008 does not need to be provided unless the display device is a portable device, and even if it is a portable device, it does not need to be provided at this location.

The display device according to this embodiment may be used as a display section of an imaging device that includes an optical section that has a plurality of lenses and an image sensor that receives light that has passed through the optical section. The imaging device may include a display unit that displays information acquired by the imaging device. Furthermore, the display section may be a display section exposed to the outside of the imaging device, or a display section disposed within the viewfinder. The imaging device may be a digital camera or a digital video camera.

FIG. 10 is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may include a viewfinder 1101, a rear display 1102, a housing 1103, and an operation unit 1104. The viewfinder 1101 may include a display device according to this embodiment. In that case, the display device may display not only the image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the moving speed of the subject, the possibility that the subject will be blocked by a shielding object, and the like.

Since the optimum timing for imaging is only a short time, it is better to display information as early as possible. Therefore, it is preferable to use a display device using the organic light emitting device of the present invention. This is because organic light emitting devices have a fast response speed. Display devices using organic light-emitting elements can be used more favorably than these devices and liquid crystal display devices, which require high display speed.

The imaging device 1100 has an optical section (not shown). The optical section has a plurality of lenses and forms an image on an image sensor housed in the housing 1103. The focus of the plural lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

The display device according to this embodiment may be used as a display section of a mobile terminal. In that case, it may have both a display function and an operation function. Examples of mobile terminals include mobile phones such as smartphones, tablets, head-mounted displays, and the like.

The display device according to this embodiment may further include a control unit that controls a display image.

FIG. 11 is a schematic diagram showing an example of an electronic device according to this embodiment. Electronic device 1200 includes a display section 1201, an operation section 1202, and a housing 1203. The housing 1203 may include a circuit, a printed circuit board including the circuit, a battery, and a communication section. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint and performs unlocking and the like. An electronic device having a communication section can also be called a communication device.

FIG. 12 is a schematic diagram showing an example of a display device according to this embodiment. FIG. 12(a) shows a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display portion 1302. The light emitting device according to this embodiment may be used for the display portion 1302.

It has a frame 1301 and a base 1303 that supports a display section 1302. The base 1303 is not limited to the form shown in FIG. 12(a). The lower side of the picture frame 1301 may also serve as a base.

Further, the frame 1301 and the display portion 1302 may be curved. The radius of curvature may be greater than or equal to 5000 mm and less than or equal to 6000 mm.

FIG. 12(b) is a schematic diagram showing another example of the display device according to this embodiment. The display device 1310 in FIG. 12(b) is configured to be foldable, and is a so-called foldable display device. The display device 1310 includes a first display section 1311, a second display section 1312, a housing 1313, and a bending point 1314. The first display section 1311 and the second display section 1312 may include the light emitting device according to this embodiment. The first display section 1311 and the second display section 1312 may be one seamless display device. The first display section 1311 and the second display section 1312 can be separated at a bending point. The first display section 1311 and the second display section 1312 may each display different images, or the first and second display sections may display one image.

The light emission brightness of the organic EL element according to this embodiment is controlled by a TFT which is an example of a switching element, and by providing a plurality of organic light emitting elements within a plane, an image can be displayed with the light emission brightness of each of the organic light emitting elements. Note that the switching element according to this embodiment is not limited to a TFT, but may be a transistor, an MIM element, or an active matrix driver formed on a substrate such as a Si substrate. On the substrate can also be referred to as inside the substrate. This is selected depending on the definition. For example, in the case of 1 inch and QVGA level of definition, it is preferable to provide the organic EL element on the Si substrate. By driving a display device using the organic EL element according to this embodiment, stable display with good image quality can be achieved even for long periods of time.

(Example 1)
The display device having the configuration shown in FIG. 1 was configured as follows.

First, aluminum was patterned on the substrate 1 as the lower electrode 2. Next, an insulating layer 5 was formed between the lower electrodes. The insulating layer 5 was formed of silicon oxide, and the layer thickness of the insulating layer 5 was 65 nm. The size of the opening in the insulating layer of each pixel was the same. The distance between pixel openings of adjacent pixels was 1.4 μm, and the distance between lower electrodes was 0.6 μm.

Next, an organic compound layer was formed on the lower electrode 2. Specifically, Compound 1 below was formed to a thickness of 3 nm as a hole injection layer. Next, Compound 2 below was formed to a thickness of 15 nm as a hole transport layer, and Compound 3 below was formed to a thickness of 10 nm as an electron blocking layer.

The first light-emitting layer was formed with a thickness of 10 nm using Compound 4 below as a host material at a weight ratio of 97% and Compound 5 below as a light-emitting dopant at a weight ratio of 3%. The second light-emitting layer was formed with a thickness of 10 nm using the following Compound 4 as a host material at a weight ratio of 98%, and the following Compound 5 and the following Compound 6 as light-emitting dopants at a weight ratio of 1% each. The electron transport layer was formed of Compound 8 below to a thickness of 110 nm. The electron injection layer was formed of lithium fluoride to a thickness of 1 nm.

Next, an MgAg alloy was formed to a thickness of 10 nm as an upper electrode. The ratio of Mg and Ag was 1:1.

Thereafter, a SiN film with a thickness of 2 μm was formed as a protective layer by CVD. Furthermore, a planarization layer was formed on the SiN film to a thickness of 300 nm by spin coating.

Next, a color filter was formed on the planarization layer. Three color filters, Red, Green, and Blue, were arranged. First, a green color filter was provided on the first organic EL element. The distance from the end of the first light emitting region on the second light emitting region side to the end L1 of the first color filter on the second light emitting region side was 0.8 μm.

Next, a blue color filter was provided on the third organic EL element. The distance from the end of the third light emitting region on the second light emitting region side to the end L4 of the third color filter on the second light emitting region side was 0.8 μm. Next, a red color filter was provided on the second organic EL element. The distance from the end of the second light emitting region on the first light emitting region side to the end L2 of the second color filter on the first light emitting region side was 1.0 μm.

The counter substrate 9 was formed of a flat glass substrate on both the upper and lower surfaces, and a filling layer 8 made of a photocurable acrylic resin was arranged between the counter substrate 9 and the color filter.

(Example 2)
It was produced in the same manner as in Example 1, except that the distance from the end of the second light emitting region on the first light emitting region side to the end L2 of the second color filter on the first light emitting region side was 1.4 μm. .

(Comparative example 1)
It was produced in the same manner as in Example 1, except that the distance from the end of the second light emitting region on the first light emitting region side to the end L2 of the second color filter on the first light emitting region side was 0.8 μm. .

(Comparative example 2)
It was produced in the same manner as Comparative Example 1, except that the distance from the end of the first light emitting region on the second light emitting region side to the end L1 of the first color filter on the second light emitting region side was 0.9 μm. .

(Evaluation results of examples and comparative examples)
A current density of 100 mA/cm2 was applied to each of the first organic EL element, second organic EL element, and third organic EL element of the organic EL display device manufactured above, and a spectral radiance meter was used to apply a current density of 100 mA/cm2 perpendicular to the substrate. The color reproduction range was evaluated by detecting light emission from the direction.

Table 3 shows a comparison of the color reproduction ranges of Example 1, Example 2, Comparative Example 1, and Comparative Example 2. The color reproduction range is the sRGB area ratio of the chromaticity u'v' space.

As shown in Table 3, it can be seen that in Example 1 and Example 2, which are embodiments of the present invention, the color reproduction range is improved compared to Comparative Example 1, that is, the color purity of the emitted color is improved.

FIG. 6 shows the relationship between L2 in Example 1, Example 2, and Comparative Example 1, and the lower electrode 2 and insulating layer 5 of the first organic EL element 100 and the second organic EL element 200. The end of the second color filter in Example 1 overlaps with the end of the lower electrode of the first organic EL element in plan view; It is thought that color mixing due to stray light can be suppressed.

In Example 2, the end of the second color filter overlaps the opening of the insulating layer of the first organic EL element in plan view. In Example 2, since color mixing due to stray light at the opening of the insulating layer of the first organic EL element can also be suppressed, the effect of improving the color reproduction range is higher.

Furthermore, in Comparative Example 2, no improvement in the color reproduction range was observed even if the first color filter having high visibility was made larger.

As described above, in the organic EL display device of the present invention, since the overlapping amount L2 of the color filter with low visibility is made larger than the overlapping amount L1 of the color filter with high visibility, the color purity of the emitted color can be improved. is possible.

1 Substrate 2 Lower electrode 3 Organic compound layer 4 Upper electrode 5 Insulating layer 6 Protective layer 7 Flattening layer 8 Filling layer 9 Counter substrate 10 Organic EL display device 20 Transmissive region 21 Overlapping region 100 First organic EL element 101 First Color filter 102 First light emitting region 200 First organic EL element 201 First color filter 202 First light emitting region 300 First organic EL element 301 First color filter 302 First light emitting region 1000 Display device 1001 Upper cover 1002 Flexible printed circuit 1003 Touch panel 1004 Flexible printed circuit 1005 Display panel 1006 Frame 1007 Circuit board 1008 Battery 1009 Lower cover 1100 Imaging device 1101 View finder 1102 Rear display 1103 Operation unit 1104 Housing 1200 Mobile device 12 01 Display section 1202 Operation section 1203 Housing 1300 Display device 1301 Frame 1302 Display portion 1303 Base 1310 Display device 1311 First display portion 1312 Second display portion 1313 Housing 1314 Bend point

Claims (18)

having a first EL element and a second EL element on the substrate,
The first EL element includes a lower electrode, a light emitting layer, an upper electrode, and a first color filter in this order from the substrate side,
The second EL element has a lower electrode, a light emitting layer, an upper electrode, and a second color filter in this order from the substrate side,
an insulating layer covering the lower electrode of the first EL element and the lower electrode of the second EL element,
The first color filter and the second color filter have an overlapping area where they overlap in plan view,
The visibility of light passing through the first color filter is greater than the visibility of light passing through the second color filter,
The distance L2 between the end of the light emitting region of the second EL element on the first color filter side and the end of the second color filter on the first EL element side is equal to A display device in which the distance L1 between the end of the light emitting region of one EL element on the second color filter side and the end of the first color filter on the second EL element side is There it is,
The insulating layer has a recess between the first EL element and the second EL element, the recess having an inclined part on the first EL element side and an inclined part on the second EL element side. have,
In plan view, the inclined portion on the first EL element side and the overlapping region overlap, and at least a portion of the inclined portion on the second EL element side and the overlapping region A display device characterized in that the images are not superimposed . The display device according to claim 1 , wherein the L2 is 25% or more larger than the L1. 3. The display device according to claim 1, wherein the L2 is larger than the L1 by 0.2 μm or more. 4. The display device according to claim 1, wherein the light emitting region of the first EL element is a region of the lower electrode that is not covered with the insulating layer. 2. The display device according to claim 1 , wherein all of the inclined portions of the recessed portions on the first EL element side in a cross section perpendicular to the substrate overlap with the overlapping region in plan view. The upper electrode of the first EL element has a stepped portion,
The step portion has a first step portion on the first EL element side and a second step portion on the second EL element side,
The display device according to any one of claims 1 to 5 , wherein the overlapping region overlaps the second stepped portion of the upper electrode in a plan view. The first color filter is a color filter that transmits green color,
7. The display device according to claim 1 , wherein the second color filter is a color filter that transmits red color. a third EL element having a third color filter having a different wavelength dispersion of absorbed light from the first color filter and the second color filter;
8. The display device according to claim 7 , wherein the third color filter is a color filter that transmits blue light. 9. The display device according to claim 1, wherein the overlapping region does not overlap with any light emitting region when viewed in plan from a direction perpendicular to the main surface of the substrate. The display device according to any one of claims 1 to 9 , wherein the first EL element and the second EL element are organic EL elements having an organic compound layer including the light emitting layer. . 11. The display device according to claim 1, further comprising a protective layer between the first color filter and the upper electrode of the first EL element. The protective layer has a stepped portion between the first EL element and the second EL element, and the stepped portion includes a first stepped portion on the first EL element side and a stepped portion on the second EL element side. It has a second step portion on the EL element side,
The display device according to claim 11 , wherein the overlapping region overlaps the first stepped portion of the protective layer in a plan view. further comprising a filling layer and a coating layer,
13. The display device according to claim 11, wherein the protective layer, the coat layer, the first color filter, and the filling layer are arranged in this order. The display device according to any one of claims 1 to 13 , further comprising a control section that controls a display image. It has a casing and a display section,
A display device, wherein the display section is the display device according to claim 1 . It has a casing and a display section,
The display unit includes the display device according to any one of claims 1 to 14 ,
The display section has a first display section and a second display section,
A display device comprising a bending point between the first display section and the second display section. It has an optical section having a plurality of lenses, an image sensor that receives the light that has passed through the optical section, and a display section that displays an image,
An imaging device, wherein the display unit is a display unit that displays an image captured by the image sensor, and the display unit includes the display device according to any one of claims 1 to 14 . It has a housing, a communication section that communicates with the outside, and a display section,
15. An electronic device, wherein the display section is the display device according to claim 1.

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